1. Technical Field
The present disclosure relates to a method for transfer printing of an electronic device, and more particularly, to a method for transfer printing of an electronic device on unconventional complex surfaces with high stability.
2. Description of the Related Art
A recent development of various types of high-end flexible electronic devices offers users a high degree of freedom in keeping, carrying, using and discarding the devices, unlike conventional formulaic rigid type of devices.
Especially, lots of developments have been made to an electronic textile (e-textile), since it has unique advantages of using a woven texture that fits the human body comfortably, while deforming naturally upon movement, and being permeable to air and sweat. To develop an e-textile, two kinds of approaches are possible.
One is to create electronic threads and interlace them, as in the applications for, for example, energy saving/converting systems, light-emitting devices, and sensors, which do not require a plurality of high density pixel arrays or highly integrated circuits.
The other is to transfer printing of devices onto a ready-made textile, which is compatible with conventional wafer-based semiconductor process technology, and thus advantageously applicable to a variety of applications such as a complex logic circuit, an electrochromic device, and tactile sensors.
When conducting a transfer printing of electronic devices onto uneven substrates including textile, human skin, animal organs, and a leaf, substantial efforts have been devoted to accommodating an interface mismatch caused due to different geometries between the devices and the substrates.
Alternatively, a polymer substrate may be made as thin as possible to ensure its mechanical flexibility and suitable patterning for efficient conformal contact on the target surfaces. The device should be made robust to external deformations by using for example stretchable or bendable buckled or serpentine structures whereby electrodes for electrical interconnect may be spaced apart from the surfaces. In addition, the adhesion between a device and a complex substrate should be sufficiently strong. To this end, for example, glue may be used to promote the interfacial adhesion, but using too much glue on a substrate such as a textile may weaken the characteristic features of the substrate, e.g., air permeability.
As such, a need exists for a transfer printing technique that would allow for a conformal transfer of a device onto complex surfaces such as a textile.
Any discussions provided in the above related art are solely for the purpose of providing a better understanding of the background art to which the present disclosure relates. It is not to be taken as an admission that any or all of these matters discussed above form part of the prior art base or were common general knowledge in the art relevant to the present disclosure as it existed before the priority date.